From: Shachar Shemesh <shachar@liveu.tv>
Date: Tue, 10 Jul 2012 04:54:13 +0000 (+0300)
Subject: tty ldisc: Close/Reopen race prevention should check the proper flag
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=40c9f61eae9098212b6906f29f30f08f7a19b5e2;p=deliverable%2Flinux.git

tty ldisc: Close/Reopen race prevention should check the proper flag

Commit acfa747b introduced the TTY_HUPPING flag to distinguish
closed TTY from currently closing ones. The test in tty_set_ldisc
still remained pointing at the old flag. This causes pppd to
sometimes lapse into uninterruptible sleep when killed and
restarted.

Signed-off-by: Shachar Shemesh <shachar@liveu.tv>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index ba8be396a621..847f7ed7a3ed 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -659,7 +659,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 		goto enable;
 	}
 
-	if (test_bit(TTY_HUPPED, &tty->flags)) {
+	if (test_bit(TTY_HUPPING, &tty->flags)) {
 		/* We were raced by the hangup method. It will have stomped
 		   the ldisc data and closed the ldisc down */
 		clear_bit(TTY_LDISC_CHANGING, &tty->flags);